English

Unitary evolution for a two-level quantum system in fractional-time scenario

Quantum Physics 2022-11-23 v2 Other Condensed Matter

Abstract

The time-evolution operator obtained from the fractional-time Schr\"{o}dinger equation (FTSE) is said to be non-unitary since it does not preserve the norm of the vector state in time. As done in the time-dependent non-Hermitian quantum formalism, for a traceless non-Hermitian two-level quantum system, we demonstrate that it is possible to map the non-unitary time-evolution operator in a unitary one. It is done by considering a dynamical Hilbert space with a time-dependent metric operator, constructed from a Hermitian time-dependent Dyson map, in respect to which the system evolves in a unitary way, and the standard quantum mechanics interpretation can be made properly. To elucidate our approach, we consider three examples of Hamiltonian operators and their corresponding unitary dynamics obtained from the solutions of FTSE, and the respective Dyson maps.

Keywords

Cite

@article{arxiv.2208.13858,
  title  = {Unitary evolution for a two-level quantum system in fractional-time scenario},
  author = {D. Cius and L. Menon and M. A. F. dos Santos and A. S. M. de Castro and F. M. Andrade},
  journal= {arXiv preprint arXiv:2208.13858},
  year   = {2022}
}

Comments

11 pages, 6 figures

R2 v1 2026-06-25T02:04:15.792Z